This site, for my personal experience, is the best to visit in the world I know of when it comes to anime and manga tbh. And why not I never enjoyed Mafia elsewhere as much as I did on here.
Not an objective statement, it usually depends on what one is subjectively looking for, unless the matter encompasses broader objective statistics either, but usually the point is to have the best subjective experience which is usually based off very specific qualities of a community rather than a broader matter, which qualities can attract an individual or a group of individuals.
This site is for example definitely not the biggest or most active around, but the intrinsic quality of the place combined with the personal attachment makes the difference for me I guess.